The latest variant, discovered by security researchers at F-Secure and dubbed OSX/Flashback.K, takes advantage of a weakness in Java SE6. That vulnerability, identified as CVE-2012-0507, allows the malware to install itself from a malicious website the user visits, without needing the user to enter an administrator’s password.

No fix is currently available for this vulnerability on the Mac, although the hole was patched in Java for Windows back in February. Unfortunately, Apple has long been criticized for lagging behind Windows when it comes to updating Java for security patches. However, given that Apple rolls out updates every few months, it seems likely that the company will distribute a patch in the not too distant future.

While there’s no need for widespread panic, the fact that this latest version of the malware can install itself without the user’s password is enough of a reason for concern that some precautions are necessary. Disabling Java is a good step, but the first line of defense is, as always, to be cognizant of the websites you visit and use common sense.